Double-ended bag and method of making same



DOUBLE-ENDED BAG AND METHOD OF MAKING SAME Fi led Au qzo, 1942 2 Sheets-Sheet 1 Illillilll v l llllllllll III I III III I l I III I l l *5 "NW '2 I Q f um-41419011650. v

May 28, 1946. H. A. RCHDIN 2,401,109

DOUBLE-ENDED BAG AND METHOD OF! MAKING SAME Filed Aug. 20, 1942 2 Sheets-Sheet 2 glwuc/rvtom Howard A. leoild b.

, Patented May as, 1946 I nouns-man mo sun rm'rnon or MAKING sum Howard A.- Rohdin, Glen Ridge, N. 1., assignmto Marjorie M. liohdin, Glen Ridge. N. J.

Application August so, 1942, Serial No. 455.483

' (Cl. ss-ss) Claims.

It is an object of my inventionto provide. a

novel form of double side seam bag having, when filled, ends of substantially identical form and appearance.

It is a further object or my invention to provide abag of the type described which is especially adapted to heat-sealing.

It is a further object of my invention to provide a bag of the type described which has a mouth formation oflering most of the advantages ofa valve bag.

It is a further object of my invention to provide an improved method for making a bag as above set forth.

These and other objects will be made clear from the following description, taken in connection with the annexed drawings in which:

Fig. 1 is a schematic view illustrating certain of my process steps;

Fig. 2 is a section on the line 2-2 of Fig. 1;

Fig. 3 is a section on the line 3-3 of Fig. 1;

Fig. 4 is a-section .on the line 4-4 of Fig. 1:

Fig. 4A is a view similar to Fig. 4, but with the bag in distended condition;

Fig. 5 is a section on the line 5-5 of Fig. 1 but showing the bag partially distended during the filling operation; I

Fig. 6 is a view similar to Fig. Bshowing the bag in final filled and closed'condition;

Fig. 6A shows an alternative sealing method;

Fig. 6B shows the final disposition of the seal formed in; Fig. 6A;

Fig. 7 is a perspective view of the final package;

Fig. 8 is a view similar to Fig. 1. but showing some optional process steps. j

Fig. 9 is a section on the line 0-9 of Fig, 8; and

Fig. 10 is a section on the line Iii-l0 of Fig. 8.

The double side seam bag, having a seamless bottom, has certain structural advantages. It

has suflered, however, from the necessity, heretofore, of beingmanufactured by a step-by-step method. By my improved structure and method, not only are all of the inherent advantages re-'- tained, but new structural advantages are added, and the manufacturing disadvantages are entirely overcome.

I have illustrated my invention as applied to a bag formed of heat-scalable material, in which situation probably maximum advantage is offered.

i" the direction of the arrow A. This web ll has previously been passed over a conventional tuber and has had formed therein a bottom gusset l2 and a top gusset M, as best shown in Fig. 2.

The departure from normal tubing practice lies' in the relationship of the margins II and it of the web l0. These, instead 'of being overlapped and sealed, are permitted to project with their respective inner surfaces in face to face contact. The width of the web is adjusted, relative to the face width and depth of gussets or the tube so that the margin I i proiectssubstantially beyond the gusset fold 20 and the margin is projects substantiallybeyond the margin l6. These margins are not secured to each other. For reasons which will be discussed in connection with Figs. 6, 6A and 6B, the projection of edge it beyond edge I.

j is desirable. It is not, however, indispensable as into superimposed relationship upon the front wall I of thetube. This condition is illustrated in Fig. 3.

When the tube is formed of material which is heat-scalable, transverse heat-seals 22 are formed across the tube, spaced at intervals corresponding to consecutive'bag widths. These seals 22 are of. substantial width and when both sides of the web in are heat-scalable, not only is the front wall I sealed to the rear wall r but these walls are sealed 85 to their adjacent gussets l2 and i4, and the gusset folds are'secured to each other. At the same time, in the area of the seal 22, the margins IS' and II are secured to each other and to the front wall f. t

40 As the tube continues to advance, bag units of the fins 24 and 28.

It is, however, entirely within the scope of my M invention to utilize non-h'eat-sealable material and to close the various seams by means of paste or preprinted areas of thermoplastic.

In Fig. l I show a web of. heat-scalable material are severed therefrom along lines lying substantially medially of the seals 22. This leaves "fins" 24 and 26 at each side of the bag, and since the material is heat-sealable the margins I 6 and I8 -(Fig. 3) are sealed to the front wall 1' in the area The next step is to fold the fins 24 and 26 against the front wall I and to secure them in such relationship by means of adhesive. Obvi ously, it is optional to fold the fins 24 and 26 against either the rear wall 1' or the front wall I. When the bag is of substantial width between the fins 24 and 26 it is advantageous to fold these fins against the front wall I. Where, however,

is, such, for example, as "Cellophane," advancing I the width between fins 2s and 26 is relatively small it is better to fold the fins against the rear wall 1'. In general, however, the normal proportions of the bag are such that front wall secure- I ment is preferred.

In Fig. 4A I illustrate the bag expanded and filled, and in this figure it is to be noted that the fins 24 and 26, secured, respectively, by patches of adhesive (and 26, lie on what have become the side walls of the bag.

In Fig. 5 I show the central section of the bag in the course of filling. The margins l6 and I8 are secured to the front wall I only at the corners, and may therefore be separated at and adjacent each side of the center. This permits the entry of a filling spout or other filling means. As the bag fills the gusset folds l2 and i4 expand to produce a fiat top and bottom.

In using material both sides of which are heat-. scalable I prefer to form the final seal as illustrated in Fig. 6. In this figure the bag has been completely filled. The gussets l2 and M are completely expanded. The margins l6 and iii are collapsed against the front wall I. With the parts in this condition I may press the package against a heated member which will exert pressure against the margins l6 and I8 in the direction of the arrow 1) and will thus effect a heatseal not only between the mutually contacting surfaces of the margins I6 and ill but between these margins and the front wall I. e

As an alternative which is desirable when an extremely tight closure is necessary I may refrain from folding over the margins l6 and I8 into contact with the front wall 1 in which case the heat-sealed areas 22 merely serve to secure the walls 1 and r and the gussets I2 and H, and the margins I6 and I8 remain in the relationship illustrated in Fig. 2. In this case, after filling.

395,859, filed May 29, 1941. Heat and pressure are then applied to form triangular sealed areas a: at each end of the bag. These triangular areas each have a leg parallel to the direction of the movement of the tube, another le at right angles angle is not critical except that it should not be the margins l6 and I8 may be projected at right angles to the wall I and subjected to heat and pressure as illustrated in Fig. 6A. This forms a seam or fin which is completely free of reentrant folds and is therefore particularly adapted to hermetic sealing. Under these conditions a great deal more pressure may be applied to the margins l6 and I8 than can be used if the closure is effected as shown in Fig. 6.

After forming a seam as shown in Fig. 6A the seam or fin may be folded against the wall 1 and secured thereto, by heat scaling in the'manner of Fig. 6, or, if desired or in the case where the interior only of the material is heat-sealable,

on'the wall I the top and bottom of the bag are identical, and the package tends to a perfect rectilinear configuration.

Figs, 8, 9 and 10 illustrate an alternative which is particularly desirable when using material,

which is either intrinsically thermoplastic or heat-scalable on both sides. In Fig. 8 I show a web I00 advancing in the direction of the arrow b. This web has been brought to tubular form precisely as shown in Figs. 1 and 2, so that there is provided a front wall I, a rear wall r, a bottom gusset ii, a top gusset l4 and margins l6 and I8 in face to face relationship. In the course of the tubing the gussets l2 and I4 are spread and a, shielding member is inserted between the folds of each gusset in the manner illustrated in my copending application, Ser. No.

less than 45. Within reasonable limits it may be somewhat greater for purposes set forth in my copending application aforesaid. This sealing step has the effect of securing walls I" and r' to the adjacent portions of the gussets l2 and i4 within the triangular areas at. This in the finished bag greatly facilitates opening to rectilinear configuration since in any and all events the areas thus sealed are never separated. Fig. 9 shows the location of the seals in the bag itself and makes it clear that the outer surfaces of the gusset folds are not mutually secured.

After the formation of the triangular sealed areas :1: a seal 22 is formed transverse the bag in precisely the manner illustrated in Fig. l. The seal 22' not only secures all of the contacting inner surfaces of the material but the contacting outer surfaces of the gussets as well. Fig. 10 is a section through the seal 22 and shows that in effect the area 22' is a prolongation of the triangular areas and that the exterior surfaces of the gussets are sealed together at y.

Following the application of the seal 22 as shown in Figs. 8 and 10 bag units are severed from the tube and their lateral fins are folded and secured as discussed in reference to Figs.

1 to 7, inclusive. The margins l6 and I8, following the formation of the triangular sealed areas 0:, may, if desired, be folded over against the front wall I in the manner illustrated in Fig. 1, and this step may be done either before or after the application of the seal 22'. If done afterthe formation of the seal 22' the margins l6 and 18' must be secured to the front wall I bymeans of adhesive rather than by means of heat sealing.

While the same steps are always performed, the sequence of the steps may be varied considerably. As previously noted, the lips IGand J8 may be folded over either before or after the formation of the cross-seals: in fact, this folding may even be postponed until after the folding of the side seams.

It may, when the bags are wide, be advantageous to seal both sides of the mouth portion inwardly from the corners so as to leave a restricted opening in the nature of a valve.- Such sealing is best done before folding of the mouth, since there are then fewer differentials of thickness. Such sealing should not, of course, include the gusset fold 20, but only the projecting portions of edges 16 and I8 and should extend inwardly from the side seams far enough to restrict the mouth opening to the desired point. This construction minimizes the leakage possibilities and insuresa larger percentage of perfect seals in the final package.

I do not intend to be limited to the precise structures shown and described but only as set forth in the subjoined claims which are to be broadly construed.

What is claimed is:

l. A method of making bags comprising: continuously forming a gu'sseted tube from a web of flexible material; controlling theforming operation to bring the margins of the web together with the inner surface of said margins in face to face contact adjacent one of the bag and forming gusset fold and with the area of such face toface contact lying outside the body of the bag severing consecutive lengths from said tube; and forming seams along the line of severance at each side of each severed length.

I 2. A method of making bags comprising: continuously forming a gusseted tube from a web of flexible material; controlling the forming operationto bring the margins of the web together with the inner surfaces of said margins in unsecontact adjacent one gusset fold and with the area of such face to face contact lying outside the body of the bag; severing consecutive lengths from said tube; and forming seams along the line of severance at each side of each severed length. n

3. A method of making bags comprising formg' a gusseted tube from a web of flexible material, controlling the forming operation to bring the margins of the web together with the inner surfaces of said margins in face to face contact adjacent one gusset fold and with the area of such face-toface contact lying outside the body directions as to intersect and traverse the gussets and said margins.

double side seams in such 4. A method of making bags comprising forming a gusseted tube from a web of flexible material, controlling the forming operation to bring the margins of the web together with the inner surfaces of said margins in unsecured face to face contact adjacent one gusset fold and with the such face to face contact lyingv outside the body of-the bag and forming double side 'seams in such directions as to intersect and traverse the gussets and said margins.

5. A double side s gusset folds, said'opening being bounded by said front wall and the adjacent wall of said gusset 'fold, saidfront wall and said adiacentwall having free edges, the, length of said front wall in the direction parallel to said Side seams being greater than that of said rear wall, and the length of said adjacent wall in the direction that of the opposite wall of said gusset, the exgusset fold being secured in said HOWARD A. ROHDIN. 

